Thunderdell, also recorded as Thunderdel, Thunderel, Thundrel, Thunderdale, or Thunderbore, was a two-headed giant

Giant (mythology)

The mythology and legends of many different cultures include monsters of human appearance but prodigious size and strength. "Giant" is the English word commonly used for such beings, derived from one of the most famed examples: the gigantes of Greek mythology.In various Indo-European mythologies,...

 of Cornwall

Cornwall

Cornwall is a unitary authority and ceremonial county of England, within the United Kingdom. It is bordered to the north and west by the Celtic Sea, to the south by the English Channel, and to the east by the county of Devon, over the River Tamar. Cornwall has a population of , and covers an area of...

 slain by Jack the Giant-Killer

Jack the Giant-killer

"Jack the Giant Killer" is a British fairy tale about a plucky lad who slays a number of giants during King Arthur's reign. The tale is characterized by violence, gore, and blood-letting. Giants are prominent in Cornish folklore and Welsh Bardic lore, but the source of "Jack the Giant Killer" is...

 in the stories of Tabart and others.

Jeff Rovin's The Encyclopedia of Monsters (New York: Facts on File, 1989) misspells Thunderdell as "Thunderel", and after describing him, proceeds to tell the basic story of Jack and the Beanstalk

Jack and the Beanstalk

Jack and the Beanstalk is a folktale said by English historian Francis Palgrave to be an oral legend that arrived in England with the Vikings. The tale is closely associated with the tale of Jack the Giant-killer. It is known under a number of versions...

with no further mention of "Thunderel", despite being the title of the entry. He then refers readers to Cormoran

Cormoran

Cormoran , also recorded as Cormilan, Cormelian, Gormillan, or Gourmaillon, was a legendary Cornish giant said to live in a cave on St Michael's Mount and terrorize the people of Penwith . He is best known as the first giant killed by Jack in the fairy tale "Jack the Giant Killer"...

.

Thunderdell is Monster in My Pocket

Monster in My Pocket

Monster in my Pocket is a media franchise developed by Morrison Entertainment Group, headed by Joe Morrison and John Weems ....

#98.